Put 1/4 cup of the coconut milk in a small saucepan and sprinkle the gelatin over. Let stand 5 minutes. Heat at low-medium heat until the gelatin dissolves (do not allow to boil). Remove from the heat and let cool.

Combine the mango, 1/2 cup coconut milk, sour cream, sugar, and coconut extract in a blender. Purée until smooth. Add the gelatin mixture and blend again. Divide mixture among 6 individual gelatin molds or wax-lined paper cups. Cover with plastic and chill at least 1 hour before serving. To serve, unmold the mousses or cut the paper cup away and invert the mousse onto chilled dessert plates. Garnish with the mango and mint.